Behaviour
Thecosomata beat their wing-like parapodia to "fly" through the water. They are holoplanktonic; that is, they spend their whole life in a planktonic form, rather than just being planktonic during the larval stage, as is more commonly the case in many marine gastropods, whose veliger larvae are part of the meroplankton.
Little is known about the behaviour of sea butterflies, but they are known to have a peculiar way of feeding. At times, they just float along, ventral-side up, with the currents. They are mostly passive plankton feeders, but at times they can be active feeders. They are generally herbivorous, entangling planktonic food through a mucous web that can be up to 5 cm wide, many times larger than themselves. If disturbed, they abandon the net and flap slowly away. When descending to deeper water, they hold their wings up. Sometimes, they swarm in large numbers and can be found washed up in flotsam, especially along the coast of eastern Australia.
Read more about this topic: Sea Butterfly
Famous quotes containing the word behaviour:
“I look on it as no trifling effort of female strength to withstand the artful and ardent solicitations of a man that is thoroughly master of our hearts. Should we in the conflict come off victorious, it hardly pays us for the pain we suffer from the experiment ... and I still persist in it that such a behaviour in any man I love would rob me of that most pleasing thought, namely, the obligation I have to him for not making such a trial.”
—Sarah Fielding (1710–1768)
“I cannot be much pleased without an appearance of truth; at least of possibility—I wish the history to be natural though the sentiments are refined; and the characters to be probable, though their behaviour is excelling.”
—Frances Burney (1752–1840)
“The quality of moral behaviour varies in inverse ratio to the number of human beings involved.”
—Aldous Huxley (1894–1963)